Infrared imaging system improves at-home skin hydration monitoring

Infrared imaging system improves at-home skin hydration monitoring

Researchers have developed a near-infrared optical system designed to provide a more objective way for individuals with atopic dermatitis to monitor skin hydration from home. The technology, detailed in APL Photonics by AIP Publishing, aims to move beyond relying on how skin feels or waiting for clinic visits to determine if a condition is improving or worsening.

Diagnosis and management of atopic dermatitis, a form of eczema, are often complicated by fluctuations in skin temperature and unclear responses to moisturizers. Conventional measurement systems often fail because they do not penetrate the deep layers of skin where the disease is most active. To address this, a team including researchers from Cardiff University, the Characteristic Medical Center of Chinese People’s Armed Police Force, and the Chinese Academy of Medical Sciences & Peking Union Medical College created a system that uses infrared imaging and a temperature-aware algorithm.

"Skin hydration matters a great deal in atopic dermatitis, but the tools used to assess it are still not ideal,"

Ting Li, researcher at the Chinese Academy of Medical Sciences & Peking Union Medical College, via miragenews.com

The team developed an optical hydration index that functions as a digital biomarker. Rather than treating the skin as a pure water slab, the researchers designed an algorithm that accounts for the biological complexity of the tissue. This approach allows the system to remain stable despite the layered nature of the skin and the challenges of measuring light reflectance beyond the surface.

Temperature was a critical component of the design. According to Li, temperature changes can shift water absorption behavior, vary tissue optical properties, alter blood flow, and subtly change how light scatters through tissue microstructure. By measuring skin-surface temperature and integrating it into a regression model, the researchers improved the stability of the system and reduced variability in real-world measurements.

The final result is a compact, noninvasive hydration-sensing system that combines multiple inputs into a single measurement score. Li stated that the goal was to create a tool more robust than superficial methods while remaining practical for repeated at-home use.

Broader applications of infrared technology in dermatology

While the new monitoring system focuses on diagnosis and tracking, other infrared technologies are used for treatment. Photobiomodulation, also known as red light therapy, utilizes red or near-infrared light to target the skin. Dr. Rachel Reynolds of the Harvard-affiliated Beth Israel Deaconess Medical Center notes that this therapy is believed to stimulate mitochondria to boost collagen production and reduce inflammation.

Different wavelengths of infrared light are utilized depending on the desired effect:

• Far-infrared: A study published via PMC highlighted that far infrared radiation between 900 to 1000 µm can increase collagen and elastin production in dermal fibroblasts.

In a study of 20 female patients with photo-aged skin, daily treatments of far infrared radiation for six months led to improvements in skin roughness and tightness. Patients reported good improvement in these areas, though the treatment did not show significant effects on hyperpigmented lesions. The study suggested that infrared radiation could be a safe, non-ablative remodeling method for wrinkles and skin texture.

However, the use of at-home therapeutic devices varies widely in strength. Dr. Reynolds observed that over-the-counter products may be weaker than professional versions, making it difficult to determine the optimal dose for specific conditions. She emphasizes that for these devices to be effective, they typically require use multiple times a week for four to six months.